CHANGES IN FETAL VESSELS OF THE LIVER 505 



where the cells had become detached or where fibrin strands 

 were in contact with the wall. In these places the endothehal 

 cells had wandered far out into the lumen along the strands of 

 fibrin. In some places there were small accumulations of endothe- 

 lial cells and not infrequently the presence of protolasmic processes 

 made them quite irregular in form. In places where a number 

 of these cells were found in a fibrin network the appearance 

 roughly simulated that of an embryonic connective tissue. These 

 endothelial cells were all well-preserved and the only cells in 

 process of degeneration were some of the blood cells contained 

 in the clot. The musculature also was well-preserved except 

 in two areas on approximately opposite sides of the lumen where 

 the outlines of the inner fibers were obliterated and their place 

 taken by irregular lumps of hyaline material which stained 

 very intensely with hematoxlyn and suggested degenerative 

 changes. No evidences of mitoses were present in the endothe- 

 lium and there was no cellular infiltration. 



From what I have seen I am inclined to believe that the 

 presence or absence of blood in the lumen of a vessel is of con- 

 siderable importance, for in not a single instance were early 

 obliterative processes observed in the empty contracted and 

 retracted distal extremities of the hypogastric arteries. It is 

 worth recalling in this connection that Haberda thought that 

 the more rapid obliteration of the arteries is due to the fact that 

 the thrombus in them is less extensive and that the walls of the 

 vessels are in contact. There is considerable variation, however, 

 in the rate of the complete contraction of the vessels for in a dog 

 which died of inanition 44 hours after birth, the vein was practi- 

 cally empty and quite well contracted throughout its extent 

 while the arteries were markedly distended with blood. But 

 in another — a still-born pup from the same litter — the conditions 

 were exactly the contrary. In the lambs examined the hypo- 

 gastric arteries were always empty save for small clots or un- 

 clotted blood here and there. The vein, on the contrary, was 

 always filled with uncoagulated blood except for the presence 

 of a small clot in the beginning of its unpaired portion and my 

 findings in this regard were entirely comparable to those of 



